POS systems, which are a type of sales management system, are commonly used in the retail industry in supermarkets, for example. In a POS system, plural terminal devices (registers) connected with a server over a network operate according to an application installed on each terminal device and perform various processes. A printer is typically disposed to each terminal device and outputs receipts and coupons as instructed by the application. Systems that are configured similarly to POS systems that produce such output include systems used in hospitals and systems used by shipping companies.
The need for functional expansion of such systems arises from improvements in technology and changing business needs after the system is introduced. However, because these systems are central to business operations and are always being used, and are connected to other systems in complex ways, modifying the application is not usually simple.
To solve this problem, ideas such as described below related to output process functions have been proposed.
Patent document 1 describes a device that renders a modem function in a personal computer that enables eliminating the microprocessor and memory that are required in a conventional modem without needing to modify an existing application program.
Patent document 2 describes a device that can access one communication port and cause a printer connected to another communication port to print simultaneously so that duplicate copies can be printed without modifying the application.